Can the Old Testament be used to say women should not wear pants?
No. Using the Old Testament verse about not wearing what pertains to a man to forbid women's pants misapplies it. In that culture men wore tunics and robes, not pants, so it cannot reasonably mean modern slacks. Such regulations were given directly to Israel under the Law and should not be forced onto believers today.
Les teaches that this is a classic example of forcing the Old Testament incorrectly. He recalls reading someone decrying women wearing slacks and using the verse, “a woman shall not wear that which pertaineth to a man.” But Les asks what men wore in Old Testament days: tunics and robes, not pants. So a woman could not wear pants or a robe, showing how foolish the application becomes. Les says we must be discerning. He affirms that things God hates in the Old Testament—drunkenness, misuse of widows, corruption among the clergy or priests—are still hateful today. However, certain commands were written directly to the Jew under the Law, and those should not be forced; they are not for us.